Rubella virus genome has conserved sequence elements both at 5'- and at 3'- .end. These sequence elements are necessary for-viral replication and transcription. To analyze the function of these elements, studies were initiated to look for proteins which interact with these elements. We observed that there are three species of phosphoproteins with Mr of 68 kDa, 63 kDa and 61 kDa which interact with the 3'-end element and three species of proteins with Mr of 97 kDa, 90 kDa and 61 kDa which interact with the 5'-end element. Among the three proteins which interact with-the 5'-end element only 61 kDa is phosphoprotein and is competed out by the 3'-end element. Studies are in progress to purify these proteins using RNAs, containing, the conserved elements that are transcribed in vitro from oligonucleotide templates, biotinylated, and incubated with unfractionated cytosol. Specific RNA-protein complexes are bound in solution to avidin and the resulting complex is bound to biotin-agarose beads. The cytosolic binding protein is released from RNA in high salt. The pure binding proteins will be sequenced and analyzed for their role in viral replication.